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On average, a pair of running shoes can last 18 months if used every day. The length of time running shoes last is exponentially distributed. What is the probability that a pair of running shoes last more than 15 months? On average, how long would six pairs of running shoes last if they are used one after the other? Eighty percent of running shoes last at most how long if used every day?

A continuous probability function is restricted to the portion between x = 0 and 7. What is P(x = 10)?

Carbon-14 is a radioactive element with a half-life of about

5,730 years. Carbon-14 is said to decay exponentially. The decay rate is 0.000121. We start with one gram of carbon-14.

We are interested in the time (years) it takes to decay carbon-14. Are the data discrete or continuous?

What is the area under f(x) if the function is a continuous probability density function?

Consider the following experiment. You are one of 100 people enlisted to take part in a study to determine the percent of nurses in America with an R.N. (registered nurse) degree. You ask nurses if they have an R.N. degree. The nurses answer 鈥測es鈥� or 鈥渘o.鈥� You then calculate the percentage of nurses with an R.N. degree. You give that percentage to your supervisor. a. What part of the experiment will yield discrete data? b. What part of the experiment will yield continuous data

For each probability and percentile problem, draw the picture.

When age is rounded to the nearest year, do the data stay continuous, or do they become discrete? Why?

Births are approximately uniformly distributed between the 52 weeks of the year. They can be said to follow a uniform distribution from one to 53 (spread of 52 weeks).

a. X ~ _________

b. Graph the probability distribution.

c. f(x) = _________

d. 矛 = _________

e. 贸 = _________

f. Find the probability that a person is born at the exact moment week 19 starts. That is, find P(x = 19) = _________

g. P(2 < x < 31) = _________

h. Find the probability that a person is born after week 40.

i. P(12 < x|x < 28) = _________

j. Find the 70th percentile.

k. Find the minimum for the upper quarter

A random number generator picks a number from one to nine in a uniform manner.

a. X ~ _________

b. Graph the probability distribution.

c. f(x) = _________

d. 渭 = _________

e. 蟽 = _________

f. P(3.5 < x < 7.25) = _________

g. P(x > 5.67)

h. P(x > 5|x > 3) = _________

i. Find the 90th percentile

According to a study by Dr. John McDougall of his live-in weight loss program, the people who follow his program lose between six and 15 pounds a month until they approach trim body weight. Let鈥檚 suppose that the weight loss is uniformly distributed. We are interested in the weight loss of a randomly selected individual following the program for one month. a. Define the random variable. X = _________ b. X ~ _________ c. Graph the probability distribution. d. f(x) = _________ e. 渭 = _________ f. 蟽 = _________ g. Find the probability that the individual lost more than ten pounds in a month. h. Suppose it is known that the individual lost more than ten pounds in a month. Find the probability that he lost less than 12 pounds in the month. i. P(7 < x < 13|x > 9) = __________. State this in a probability question, similarly to parts g and h, draw the picture, and find the probability.

A subway train arrives every eight minutes during rush hour. We are interested in the length of time a commuter must wait for a train to arrive. The time follows a uniform distribution. a. Define the random variable. X = _______ b. X ~ _______ c. Graph the probability distribution. d. f(x) = _______ e. 渭 = _______ f. 蟽 = _______ g. Find the probability that the commuter waits less than one minute. h. Find the probability that the commuter waits between three and four minutes. i. Sixty percent of commuters wait more than how long for the train? State this in a probability question, similarly to parts g and h, draw the picture, and find the probabilit